It is known to provide a vehicle safety system including one or more actuatable vehicle occupant protection devices, such as airbags, for helping to protect an occupant upon the occurrence of a vehicle crash event. Such safety systems include an airbag electronic control unit (ECU) and crash sensors (e.g., accelerometers, pressure sensors) positioned at various locations throughout the vehicle. The sensors provide data related to sensed vehicle conditions, which the airbag ECU uses to determine the type of crash that has occurred and which, if any, of the protection devices to actuate. Airbag ECUs also include crash sensors (e.g., accelerometers) that are used to make the baseline determination that the vehicle crash event has occurred/is occurring. Airbag ECUs also include inertia sensors (e.g., gyroscopes) that are used to determine roll conditions of the vehicle. To do this, the airbag ECU monitors the attitude of the vehicle and measures roll about the X, Y, and Z axes. To make these measurements, it is important that the airbag ECU be positioned as close as possible to the vehicle center of gravity.
The center of gravity for most vehicles is close in a position low in the vehicle and forward in the area of the front of the passenger compartment, such as in the area of the instrument panel/center console. As such, the most convenient place to mount the airbag ECU and its associated sensors in the center tunnel of the vehicle—the space exterior to the vehicle cabin where certain drive train components, such as the vehicle transmission and/or driveshaft are located. Space in the center tunnel is limited and the conditions in that location are harsh, as it can be exposed directly or indirectly to the exterior operating environment of the vehicle. Additionally, since the airbag ECU relies on many electrical connections with its associated sensors, the airbags it controls, and with other vehicle systems, such as a body control module (BCM), wiring can be difficult and the potential for contamination/corrosion of contacts can be heightened.